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Hi ZRX,
I rarely see a spring that I think needs to be replaced.
This one appears to me to be at the end of it's life.
Finding a replacement spring that won't cause ride height problems (in the other direction... too high) isn't easy.
What are your plans for this car... will you attempt to replace things that need to be replaced with service and reproduction parts or will you put aftermarket/ modified parts on it.
Knowing that will help folks give you suggestions on how to proceed.
Regards,
Alan
Hi ZRX,
I rarely see a spring that I think needs to be replaced.
This one appears to me to be at the end of it's life.
Finding a replacement spring that won't cause ride height problems (in the other direction... too high) isn't easy.
What are your plans for this car... will you attempt to replace things that need to be replaced with service and reproduction parts or will you put aftermarket/ modified parts on it.
Knowing that will help folks give you suggestions on how to proceed.
Regards,
Alan
I agree. That spring doesn't look right. Unless it's some kind of fancy re-arched road race spring, your car should not be that low with a 6.5" bolt.
Hi ZRX,
I rarely see a spring that I think needs to be replaced.
This one appears to me to be at the end of it's life.
Finding a replacement spring that won't cause ride height problems (in the other direction... too high) isn't easy.
What are your plans for this car... will you attempt to replace things that need to be replaced with service and reproduction parts or will you put aftermarket/ modified parts on it.
Knowing that will help folks give you suggestions on how to proceed.
Regards,
Alan
Great question, Alan. And one that I'm not sure how to answer just yet. Being that my car is mostly unmolested, I would love to keep the car as original as possible, but understand of course that safety is a priority (like radial tires vs. bias ply). In order of importance, I suppose my priorities are 1. Ride height & safety, 2. Originality, and a very close #3 is cost.
Here's where I put the question to you in the forum: How big of a deal is it to have a non-original leaf spring on a mostly original car? It makes sense that if someone were to change out the rear suspension for a different system that the value could take a hit to those who prefer all original cars. But to only change out the leaf spring? I'm too new to this to know the effect. Pros and cons from you all would be greatly appreciated. Or, if this has been written about in the forum already (I've read some other threads as well), please feel free to point me in the right direction.
Obviously do as you wish. But this is what I see and will comment on.
I use the rubber cushions for the rear leaf spring and not the polyurethane ones....because I have had many of the polyurethane ones crack up and disintegrate. SO..I stick with rubber.
In the photo below I am concerned if I am actually seeing a repair and a crack in the rear end cover on the outer left bolt that holds the rear leaf spring in.
Then this is bringing me to the next thing I see.
In the photo...the adjustment of your strut rod is basically at the end of its maximum travel for adjustment.
Which is telling me that either:
1.) The strut rod bushings are shot and needing to be replaced.
2.) The side yokes in your differential are worn down and now it is getting very close to not being able to be adjusted using the concentric bolts GM designed.
3.) Both.
Also...bad rear shocks and a bad rear leaf spring do effect the condition of the side yokes.
And I agree with the general consensus about the rear leaf that it is basically shot.
Here's where I put the question to you in the forum: How big of a deal is it to have a non-original leaf spring on a mostly original car? It makes sense that if someone were to change out the rear suspension for a different system that the value could take a hit to those who prefer all original cars. But to only change out the leaf spring? I'm too new to this to know the effect. Pros and cons from you all would be greatly appreciated. Or, if this has been written about in the forum already (I've read some other threads as well), please feel free to point me in the right direction.
Thanks.
Obviously you can keep the original for the next owner in the future if you are concerned that throwing it away would effect the resale cost.
When selling your car in the future. It will depend on what 'target market' you are going for. So..some people would absolutely out if it were not there and make it out like it is the worst thing ever.....while others would not even blink at it.
SO..decide on how you want keep your car and maintain it when stuff needs repair. Because some people will pick your car to death and tell you kn how much is wrong with it and then tell you what it is worth....while other people who do not care....just want a car that is really really nice and if there are somethings that are not factory correct...they do not care because they are going to be driving it and not have it stuck in their garage all the time.
I have a friend who stops by my shop from time to time when I have an original Corvette that came in. He will pick a 1968-1969 to death and tell me all what is wrong with it....(like I already do not know) but I do not care due to it is not my car... and I am not being paid for consulting and fixing any of what he sees that is not factory correct. All I am doing is repairing what the owner wants.
So... make yourself happy and do your Corvette as YOU see fit. Because a 1970 I had done that goes to shows around here is NOT 100% factory original...but it is so sweet ...that I can tell you that he would have NO problem in selling it and getting top dollar for it. Just saying.
Case in point...in the thread below is the Donneybrook Green 1970 Corvette I mentioned that I did when it was at a major show. Start at POST#25.
And maybe shop for an original that is not shot to have as a USABLE spare original part for next owner. Instead of keeping a spring that is worth about 5 cents a pound.
Obviously do as you wish. But this is what I see and will comment on.
I use the rubber cushions for the rear leaf spring and not the polyurethane ones....because I have had many of the polyurethane ones crack up and disintegrate. SO..I stick with rubber.
In the photo below I am concerned if I am actually seeing a repair and a crack in the rear end cover on the outer left bolt that holds the rear leaf spring in.
Then this is bringing me to the next thing I see.
In the photo...the adjustment of your strut rod is basically at the end of its maximum travel for adjustment.
Which is telling me that either:
1.) The strut rod bushings are shot and needing to be replaced.
2.) The side yokes in your differential are worn down and now it is getting very close to not being able to be adjusted using the concentric bolts GM designed.
3.) Both.
Also...bad rear shocks and a bad rear leaf spring do effect the condition of the side yokes.
And I agree with the general consensus about the rear leaf that it is basically shot.
DUB
Nice catch Dub. After blowing it up, I said wow, it does looked cracked which would be a bad thing. I would definitely checked that out real good.
Definitely a keen eye, DUB. I never noticed it myself, and I was a foot from it. It does look like there was some type of repair there. Would that be JB Weld? Thanks for the other insight as well, on the other components.
Now my question is, what exactly does that repair mean? Is it common to make repairs like that? If it wasn't structurally sound, wouldn't it have given way by now? Whenever it was done, it must have been a long time ago. Secondly, if I were to unbolt the spring and re-bolt the new one, I'm wondering if it could take the stress of the process... I suppose the smart thing to do is to research what would be involved in buying a new differential, I'm sure [CORRECTION: Differential Cover]. I can hear it now... "Welcome to the wonderful world of classic car ownership..."
Last edited by ZRXGreen; 03-12-2018 at 08:21 AM.
Reason: Correction
Everyone here is being too polite and politically correct. You flat out and absolutely need to replace the spring, the rear cover, get your strut Rods rebuilt, and get some good inner axles is a start! You have no value with these worn out and compromised parts!
Those parts in their State are junk, originality thoughts as related to some sort of value, would be a joke!
Last edited by TCracingCA; 03-12-2018 at 01:39 AM.
If you find there is a crack in the housing, now is the time do start replacing old worn parts with new ones and rebuilding what ever you touch. Weather you go original or modify is up to you. As long as you use quality parts you won't hurt the value of your car if you don't keep it all original. take your time and do it right.
If you find there is a crack in the housing, now is the time do start replacing old worn parts with new ones and rebuilding what ever you touch. Weather you go original or modify is up to you. As long as you use quality parts you won't hurt the value of your car if you don't keep it all original. take your time and do it right.
Hi ZRX,
"Being that my car is mostly unmolested, I would love to keep the car as original as possible."
Doing this is very possible!...it's not always easy though!! It's not at all important to many owners, but is very important to others.
I think you'll need to assess just what you have, and then what parts can be reused, what parts need to be rebuilt/restored, and what parts will need to be replaced with new parts.
Just buying all new parts is quick and easy, (but expensive), but too often brings new problems to the car.
So, be cautious how you proceed.
Regards,
Alan
I think it's wise to judge each part's viability individually. It will vary from car to car.
No new parts here except for new bearings in the trailing arms.
Hi ZRX,
"Being that my car is mostly unmolested, I would love to keep the car as original as possible."
Doing this is very possible!...it's not always easy though!! It's not at all important to many owners, but is very important to others.
I think you'll need to assess just what you have, and then what parts can be reused, what parts need to be rebuilt/restored, and what parts will need to be replaced with new parts.
Just buying all new parts is quick and easy, (but expensive), but too often brings new problems to the car.
So, be cautious how you proceed.
Regards,
Alan
I think it's wise to judge each part's viability individually. It will vary from car to car.
No new parts here except for new bearings in the trailing arms.
Thank you Alan. That looks amazing! Was your spring reconditioned?
Hi ZRX,
Yes, that's the original spring and spring liners.
This car has only 46,000 miles on it so the spring was still usable. (In fact I wish it WOULD sag a little so the rear of the car would sit a little lower.)
I stripped and repainted the spring and reused all but one liner.
Regards,
Alan
Now my question is, what exactly does that repair mean?
Someone did not want to go in and remove the rear differential and replace the cover...so they slapped something on it.
Is it common to make repairs like that?
It is common for those people who try to find the easy way out and not repair it correctly becasue they either do not have the skills or desire to fix it. Like it ash been said many many times. Any person can own a Corvette but not all of those people maintain it correctly.
For someone like myself...I would not do that.
If it wasn't structurally sound, wouldn't it have given way by now?
Who knows...but logic basically would tell us that IF there is a crack in cast iron..it is NOT going to stop and in time...it will fail. Probably the reason it has not snapped off is due to your rear leaf spring is shot...and I do not think you have actually raised it fully off the ground. And if you have done so.,.,the arc in the spring is so weak due to being worn out...it does not have enough power in it to cause this to crack off.
Whenever it was done, it must have been a long time ago. Secondly, if I were to unbolt the spring and re-bolt the new one, I'm wondering if it could take the stress of the process.
Chances are really high if you go to unbolt that bolt...that 'ear' of the rear end cover will fall off.
.. I suppose the smart thing to do is to research what would be involved in buying a new differential, I'm sure [CORRECTION: Differential Cover]. I can hear it now... "Welcome to the wonderful world of classic car ownership..."
I will say this...and I know you may not want to 'hear' it. but IF you drop the rear end to replace the rear end cove with a new aftermarket one that has more material so this does not happen like the origianls one can do ( or find a used original and take your chances). I would seriously advise you to COMPLETELY check out your differential and have it serviced while you have it out. Worn clutches and side yokes are generally a common issue. And IF oyu choose to leave it alone..and oyu have excessive play in your side yokes..I can tell you that if left unattended...the side yokes can wear down so much that the dust shield on them actually eat into the housing of the differential and make it so the grease seals for the side yokes can not even be installed due to the lands in the housing have been worn away. Just saying.
And I also understand that some people only drive their Corvette 500 miles a year...so...that can also be taken into account if you choose to not do anything to parts that are worn.
If you need to know how to check your rear differential clutches...call me or it is in a service manual. Just make sure that the wheel can turn clockwise and the car is in gear and NOT binding due to the suspension is in a pinch....becasue the rear of the car MUST be off the ground.
And not that it matters. But I always suggest hat if strut rods need servicing..i try to advise my customer sto get the grease-able heim jointed adjustable strut rods. Because in time...due to the X,Y Z motion the strut rod goes through ...the spherical ( heim jointed) ends work perfectly. The rubber bushing can fail and do fail and mainly the bushing under the differential. And with then begin a 'bolt on' part that is somewhat easy to service...people should not freak out and actually appreciate them being there....unless they are looking for 1900% originality.
And once again...if you are driving it a few hundred miles a year...then do what you want that makes you happy.
You are getting excellent advice from Alan71 and DUB.
Decide what you want to do with your car (keep basically original or modify) and how you plan to drive it (cruise, race, show), then build it the way you want.
You know the spring is shot and the differential cover should be replaced.
Decide if you want to modify the suspension or keep it stock, then find the replacement parts you need to replace the spring.
Drop the differential and have it checked inside and out replacing what is needed including the cover.
As you can see Alan has done beautiful work using the OEM parts. You can as well.
When my project is completed my car will look stock except the wheels and the stance.
The interior will be stock except for the 5 speed pattern on the console.
Pop the hood or crawl underneath and you'll find everything is heavily modified.
Whatever you do just do it right.
I will say this...and I know you may not want to 'hear' it. but IF you drop the rear end to replace the rear end cove with a new aftermarket one that has more material so this does not happen like the origianls one can do ( or find a used original and take your chances). I would seriously advise you to COMPLETELY check out your differential and have it serviced while you have it out. Worn clutches and side yokes are generally a common issue. And IF oyu choose to leave it alone..and oyu have excessive play in your side yokes..I can tell you that if left unattended...the side yokes can wear down so much that the dust shield on them actually eat into the housing of the differential and make it so the grease seals for the side yokes can not even be installed due to the lands in the housing have been worn away. Just saying.
And I also understand that some people only drive their Corvette 500 miles a year...so...that can also be taken into account if you choose to not do anything to parts that are worn.
If you need to know how to check your rear differential clutches...call me or it is in a service manual. Just make sure that the wheel can turn clockwise and the car is in gear and NOT binding due to the suspension is in a pinch....becasue the rear of the car MUST be off the ground.
And not that it matters. But I always suggest hat if strut rods need servicing..i try to advise my customer sto get the grease-able heim jointed adjustable strut rods. Because in time...due to the X,Y Z motion the strut rod goes through ...the spherical ( heim jointed) ends work perfectly. The rubber bushing can fail and do fail and mainly the bushing under the differential. And with then begin a 'bolt on' part that is somewhat easy to service...people should not freak out and actually appreciate them being there....unless they are looking for 1900% originality.
And once again...if you are driving it a few hundred miles a year...then do what you want that makes you happy.
DUB
Thanks so much, DUB. Great advice... I have a lot to think about!
You are getting excellent advice from Alan71 and DUB.
Decide what you want to do with your car (keep basically original or modify) and how you plan to drive it (cruise, race, show), then build it the way you want.
You know the spring is shot and the differential cover should be replaced.
Decide if you want to modify the suspension or keep it stock, then find the replacement parts you need to replace the spring.
Drop the differential and have it checked inside and out replacing what is needed including the cover.
As you can see Alan has done beautiful work using the OEM parts. You can as well.
When my project is completed my car will look stock except the wheels and the stance.
The interior will be stock except for the 5 speed pattern on the console.
Pop the hood or crawl underneath and you'll find everything is heavily modified.
Whatever you do just do it right.
Thank you, OCB. This forum is really awesome. Thanks to all who have tried to help.
I do think many dance around timid to give advice. Many make sure what they write is going to be the consensus of the group! I am just a little more direct, when I have time to give an entire proper reply!
It was was an awesome spot on the cracked rear cover!
I guess I am lucky being in California and having cars first sold in California, because many of you guys have undersides that look pretty bad!
Last edited by TCracingCA; 03-15-2018 at 10:57 AM.
03-10-2018, 05:14 PM
out if it were not there and make it out like it is the worst thing ever.....while others would not even blink at it. 
Nice catch Dub. 
After blowing it up, I said wow, it does looked cracked which would be a bad thing. I would definitely checked that out real good. 
